Owing to a rapid increase of electric and electronic parts to be mounted on a car body, there is an increase in the number of electric junction boxes, to be connected with a wire harness for use in the car body, which accommodates a printed-circuit board having electric and electronic parts mounted thereon.
The electric junction box of this kind in which an internal circuit is constructed of a bus bar laminate consisting of bus bars and insulating plates alternately layered thereon and a printed-circuit board having electronic parts mounted thereon is disclosed in Japanese Patent Application Laid-Open No. 9-233650 (patent document 1) and the like.
As shown in FIG. 6, the electric junction box 1 disclosed in the patent document 1 accommodates in the casing thereof the laminate 4 consisting of the bus bars 2 and the insulating plates 3 alternately layered thereon and the circuit substrate (printed-circuit board) 6 having the electronic parts 5 mounted thereon. The supporting bus bar tabs 2a projected from the bus bars 2 support the circuit substrate 6. The connecting bus bar 2b projected from the bus bars 2 is inserted into the connector 6a provided on the circuit substrate 6 to electrically connect the bus bars 2 with the electric conductor of the circuit substrate 6.
As described above, the circuit of the printed-circuit board is connected with the bus bars through the connector and with a connector of a wire harness of an external circuit through the bus bars. Therefore with an increase of relays and the like to be mounted on the printed-circuit board, the number of layers of the bus bars increases. Consequently the electric junction box becomes large and complicated in its construction.
Patent document 1: Japanese Patent Application Laid-Open No. 9-233650